Method and system for automatic configuration of virtual talk groups based on location of media sources

ABSTRACT

A method for automatic configuration of virtual talk groups based on location of media source includes monitoring communications from a plurality of mobile endpoints. Each communication comprises a media message and location information identifying a location of its transmitting endpoint. The method includes selecting a first group of mobile endpoints of the plurality of endpoints according to virtual talk group configuration instructions based on the locations of the mobile endpoints. The method also includes configuring a first virtual talk group comprising the first group of mobile endpoints to facilitate communications among the first group of mobile endpoints. The first group of mobile endpoints comprises mobile endpoints of different communication networks.

TECHNICAL FIELD OF THE INVENTION

This invention relates in general to communication systems and, moreparticularly, to a method and system for automatic configuration ofvirtual talk groups based on location of media source.

RELATED APPLICATION

This application is related to U.S. patent application Ser. No.11/202,403, entitled “METHOD AND SYSTEM FOR PROVIDING INTEROPERABLECOMMUNICATIONS WITH LOCATION INFORMATION,” filed concurrently with thepresent application, and to U.S. patent application Ser. No. 11/202,400,entitled “METHOD AND SYSTEM FOR COMMUNICATING MEDIA BASED ON LOCATION OFMEDIA SOURCE,” filed concurrently with the present application.

BACKGROUND OF THE INVENTION

Many public and private groups, such as security and safety personnel(e.g., police, fire fighters and ambulance drivers) use variouscommunication networks of differing technologies and types forcommunication. Many networks utilize land mobile radios communicatingthrough push-to-talk technologies. However, communications amongdifferent endpoints of different networks such as endpoints of differentpolice, fire or other security networks may be difficult. Collaborationbetween the different agencies and networks tends to be ad hoc andinefficient. When achieved, it often involves laborious manualintervention. Organizations working towards interoperability solutionsinclude Raytheon JPS Communications, IP Blue, Twisted Pair, M/A-COM andCisco Systems.

SUMMARY OF THE INVENTION

The present invention provides a method and system for automaticconfiguration of virtual talk groups based on location of media sourcethat substantially eliminates or reduces at least some of thedisadvantages and problems associated with previous methods and systems.

In accordance with a particular embodiment, a method for providinginteroperable communications with location information includesreceiving communications from a plurality of virtual talk groups. Eachvirtual talk group comprises a plurality of endpoints of differentcommunication networks. The method includes receiving from a firstmobile endpoint of a first virtual talk group of the plurality ofvirtual talk groups a first communication. The first communicationcomprises a first media message and location information identifying alocation of the first mobile endpoint. The method includes presenting toa user the first media message from the first mobile endpoint and thelocation of the first mobile endpoint.

In accordance with another embodiment, a method for automaticconfiguration of virtual talk groups based on location of media sourceincludes monitoring communications from a plurality of mobile endpoints.Each communication comprises a media message and location informationidentifying a location of its transmitting endpoint. The method includesselecting a first group of mobile endpoints of the plurality ofendpoints according to virtual talk group configuration instructionsbased on the locations of the mobile endpoints. The method also includesconfiguring a first virtual talk group comprising the first group ofmobile endpoints to facilitate communications among the first group ofmobile endpoints. The first group of mobile endpoints comprises mobileendpoints of different communication networks.

In accordance with an additional embodiment, a method for communicatingmedia based on location of media source includes receivingcommunications from a plurality of endpoints. Each communicationcomprises a media message and location information identifying alocation of its transmitting endpoint. The method includes receiving aselection of a geographical area and comparing the location informationof each communication with the selected geographical area. The methodalso includes presenting to a user each message received from eachendpoint of the plurality of endpoints located within the selectedgeographical area.

Technical advantages of particular embodiments include systems andmethods for providing interoperable communications among endpoints ofvarious types that utilize differing technologies. Virtual talk groupsmay be created dynamically to enable communication among a subset ofendpoints for particular circumstances, such as particular securityevents that arise. Particular embodiments present to a user locationinformation of an endpoint communicating through an interoperablecommunication system so that the user may more easily monitor variousendpoints and various virtual talk groups of a subset of endpoints. As aresult, the user may be better able to make decisions based on currentcommunications. Embodiments may also provide an identification of aparticular virtual talk group of which the communicating endpoint is amember, particularly when a user is receiving communications fromendpoints of a plurality of virtual talk groups.

In addition, in some embodiments a user may be able to select ageographical area and receive interoperable communications from allendpoints within the selected geographical area. For example, the user'sendpoint may receive communications from a plurality of endpoints frommultiple areas and may filter those communications to present to theuser only communications from endpoints transmitting from the selectedgeographical area. This enables a user to monitor only communications ofinterest for critical security or other needs. Moreover, particularembodiments provide automated configuration of endpoints into virtualtalk groups based on the locations of the endpoints. For example,according to configuration instructions from a user, a virtual talkgroup may be automatically configured as including endpoints of aparticular neighborhood, such as endpoints within a configurabledistance from an event or as all endpoints who are in proximity to theuser.

Other technical advantages will be readily apparent to one skilled inthe art from the following figures, descriptions and claims. Moreover,while specific advantages have been enumerated above, variousembodiments may include all, some or none of the enumerated advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and itsadvantages, reference is now made to the following description, taken inconjunction with the accompanying drawings, in which:

FIG. 1 illustrates a communication system with various communicationnetworks and an interoperability system, in accordance with a particularembodiment;

FIG. 2 illustrates an example interoperability system, in accordancewith a particular embodiment;

FIG. 3 illustrates an example endpoint, in accordance with a particularembodiment;

FIG. 4 illustrates an example display used in providing interoperablecommunications with location information, in accordance with aparticular embodiment;

FIG. 5 illustrates an example display used for communicating media basedon location of media source, in accordance with a particular embodiment;

FIG. 6 illustrates an example display used in providing interoperablecommunications according to scene-related virtual talk groups, inaccordance with a particular embodiment;

FIG. 7 illustrates a method for providing interoperable communicationswith location information, in accordance with a particular embodiment;

FIG. 8 illustrates a method for communicating media based on location ofmedia source, in accordance with a particular embodiment; and

FIG. 9 illustrates a method for automatic configuration of virtual talkgroups based on location of media source, in accordance with aparticular embodiment.

DETAILED DESCRIPTION

FIG. 1 illustrates a communication system 10, in accordance with aparticular embodiment. Communication system 10 includes communicationnetworks 24 a-24 e, interoperability system (IS) 20 and endpoints 22a-22 c. IS 20 is able to facilitate interoperable communication sessionsbetween and among various communication devices, such as endpoints ofcommunication networks 24 and endpoints 22. IS 20 uses a systemsapproach to offer a framework based on IP protocols and services toimmediately achieve secure voice, video and other data interoperabilityamong communication endpoints and networks utilizing differenttechnologies.

In particular embodiments when a user of a mobile endpoint communicatesaudio, video or other information to one or more other endpoints, GPSinformation identifying the mobile endpoint's location is included inthe transmission such that the mobile endpoint's location can bepresented to the one or more other endpoints in connection with thecommunicated audio, video or other information. In some embodiments, GPSinformation may be steganographically embedded within a communicationstream, such as a voice stream. The communication of locationinformation may be used to notify a user monitoring various endpointsand various virtual talk groups of a subset of endpoints of the locationof a particular transmitting endpoint. Thus, the user may be better ableto make decisions based on current communications.

In some embodiments, a user may be able to select a geographical areaand have presented by the user's endpoint communications from allendpoints within the selected geographical area. The endpoint mayreceive communications from additional endpoints but may filter out forpresentation to its users only those communications from endpointswithin the selected area. This enables a user to monitor onlycommunications of interest for critical security or other needs.

Moreover, particular embodiments provide automated configuration ofendpoints into virtual talk groups based on the locations of theendpoints. For example, according to configuration instructions from auser, a virtual talk group may be automatically configured as includingendpoints of a particular neighborhood, such as endpoints within aconfigurable distance from an event or as all endpoints who are inproximity to the user.

In the illustrated embodiment, communication networks 24 a and 24 dcomprise radio networks (RNs), communication network 24 b comprises alocal area network (LAN), communication network 24 c comprises a PSTNand communication network 24 e comprises an IP network. It should beunderstood, however, that communication system 10 may comprise anynumber of IP or non-IP communication networks of any wireless orwireline form capable of communicating audio and/or videotelecommunication signals, data, and/or messages, including signals,data or messages. Communication networks 24 a-24 e may include anynumber and combination of segments, nodes and endpoints to enablecommunication among network devices and components. Communicationnetworks 24 a-24 e may be distributed locally or across multiple citiesand geographic regions. Nodes may include any combination of networkcomponents, gatekeepers, call managers, conference bridges, routers,hubs, switches, gateways, base stations, endpoints or other hardware,software or embedded logic implementing any number of communicationprotocols that allow for the exchange of data in communication system10. Segments 30, which may comprise any suitable wireless or wirelinecommunication links, including one or more communication networks (e.g.,WANs) as appropriate, couple various networks with each other and withendpoints 22 and IS 20. In particular embodiments, segments may includegateways for facilitating communication between various networks, suchas an LMR gateway between radio network 24 a and IP network 24 e.

In some cases, users of endpoints of one of communication networks 24a-24 e may communicate with endpoints of another of communicationnetworks 24 a-24 e through IS 20. A radio network, such as radio network24 a or 24 d, may support communication among portable mobile stationendpoints, such as land mobile radios (LMRs), using any suitablecommunication methods or features, such as cellular and push-to-talk(PTT). Communication networks 24 a-24 e may comprise networks ofparticular groups or agencies (e.g., a municipality's police departmentnetwork), whether operational with respect to a particular area orotherwise.

IS 20 enables, facilitates and/or provides for interoperablecommunication among communication endpoints and devices, such as LMRs,cellular phones, IP phones, PCs, PDAs, PSTN phones, video monitors,cameras and sensors of one or more communication networks (e.g.,communication networks 24 a-24 e) using Internet Protocol. Suchendpoints may comprise IP or non-IP-enabled endpoints. In particularembodiments, IS 20 may control gateways (for example, of segments 30) inorder to map radio frequencies of particular mobile radio endpoints toIP addresses for communication to other types of radio endpoints or IPdevices. For example, a particular gateway may be able to receivecommunications from various types of endpoints (e.g., on various typesof communication networks) and may convert such communications fortransmission to other types of endpoints. IS 20's control of the gatewaymay control the various endpoints and/or networks that receiveparticular communications, depending on system functionality andconfiguration as further discussed below. As indicated, such control mayinclude the mapping of communications and endpoints to IP addresses forinteroperable communication. In some embodiments, IS 20 may host audioconferences that bridge communications received from endpoints. Asindicated above, communication system 10 (including IS 20) may includeany suitable number or type of gateways (e.g., LMR and PSTN gateways),servers (e.g., multipoint conference servers), switches, routers,firewalls, access points, processors, memory or other hardware, softwareor encoded logic to provide functionality described herein. IS 20 iscoupled to communication networks 24 a-24 d and endpoints 22 through IPnetwork 24 e, which may comprise any suitable IP network.

As indicated above, IS 20 uses IP to enable communication amongendpoints of various networks. The manner in which IS 20 facilitatescommunications among endpoints may vary according to location and systemor operational needs. For example, IS 20 may communicate with endpointsusing multicast IP addresses assigned to an endpoint of a communicationnetwork, a group of endpoints of a communication network or one or moreendpoints of multiple communication networks or alternatively using apeer to peer dialed connection or a nailed dialed connection. A group ofendpoints may be combined into a virtual talk group for communicationusing a particular IP address. As an example, the virtual talk group maybe assigned a multicast IP address through which users of variousendpoints may communicate on the talk group. The use of multicast IPaddresses allows IS 20 to facilitate communications among communicationdevices and endpoints of various communication networks to provideaudio, data, video and control network interoperability. As anadditional example, in some cases multicast streams (e.g., utilizingmulticast IP addresses) may be used. In some cases nailed dialedconnections, such as those using SIP protocol, may be used forcommunication among endpoints and with IS 20. Various embodiments maycombine communication methods to facilitate communication amongendpoints. For example, in some cases certain endpoints of a virtualtalk group may participate in the talk group through a multicast IPaddress while other endpoints may utilize a nailed SIP connection. IS 20may control this participation, such as by controlling gateways,multipoint conferences and the mapping of communications to IPaddresses.

IS 20 may be utilized and implemented in any number of market segments,such as enterprise safety and security (e.g., loss prevention),transportation, retail, public safety and federal agencies in order toprovide radio and non-radio network interoperability within and betweensuch market segments. As indicated above, such network interoperabilityincludes the interoperability of push-to-talk voice technology withinvarious networks and the interoperability between push-to-talk and fullduplex dialed connections.

It will be recognized by those of ordinary skill in the art thatendpoints 22 and IS 20 may be any combination of hardware, software,and/or encoded logic that provides communication services to a user. Inthe illustrated embodiment, endpoints 22 comprise a PC (endpoint 22 a),a PDA (endpoint 22 b) and an IP phone 22 c). However, in otherembodiments, endpoints 22 may include a telephone, a personal computer(PC), a video monitor, a camera, an IP phone, a cell phone, a landmobile radio (LMR), a personal digital assistant (PDA), a command centeror any other communication hardware, software and/or encoded logic thatsupports the communication of audio, video or other data, using packetsof media (or frames) or otherwise, through communication system 10.Endpoints 22 as well as endpoints and components of communicationnetworks 24 may be capable of communicating using any particular type oftechnology, such as cellular, IP, PSTN, CDMA, GSM, TDMA and satellite.Endpoints 22 and IS 20 may also include unattended or automated systems,gateways, other intermediate components or other devices that canestablish media sessions.

Although the illustrated embodiment includes five communication networks24 a-24 e, the term “communication network” should be interpreted asgenerally defining any network capable of transmitting audio and/orvideo telecommunication signals, data, and/or messages, includingsignals, data or messages. Any one of networks 24 a-24 e may beimplemented as a local area network (LAN), wide area network (WAN),cellular network, global distributed network such as the Internet,Intranet, Extranet, PSTN, LMR network, CDMA network, GSM network, TDMAnetwork, satellite network or any other form of wireless or wirelinecommunication network.

Communications over communication networks 24 a-24 e may use anysuitable communication protocol. In a particular embodiment, somecommunication networks may employ voice communication protocols thatallow for the addressing or identification of endpoints, nodes, and/orother components coupled to the communication network. For example,using Internet protocol (IP), each of the components coupled togetherby, for example, communication network 24 b in communication system 10may be identified in information directed using IP addresses. In thismanner, network 24 b may support any form and/or combination ofpoint-to-point, multicast, unicast, or other techniques for exchangingmedia packets among components in communication system 10. Any networkcomponents capable of exchanging audio, video, or other data areincluded within the scope of the present invention.

Since IP networks share a common method of transmitting data,telecommunication signals may be transmitted between telephony deviceslocated on different, but interconnected, IP networks. In addition tobeing coupled to other IP networks, communication network 24 b may alsobe coupled to non-IP telecommunication networks, for example through theuse of interfaces or components, including gateways. In the illustratedembodiment, communication network 24 b may be coupled with PSTN 24 cthrough a gateway. In some embodiments the gateway may be a part of IS20 or network 24 e.PSTN 24 c includes switching stations, centraloffices, mobile telephone switching offices, pager switching offices,remote terminals, and other related telecommunications equipment thatare located throughout the world. IP networks transmit data (includingvoice and video data) by placing the data in packets and sending eachpacket individually to the selected destination, along one or morecommunication paths. Unlike a circuit-switched network (like PSTN 24 c),a dedicated circuit is not required for the duration of a call or faxtransmission over IP networks.

Technology that allows telecommunications to be transmitted over an IPnetwork may comprise Voice over IP (VOIP), or simply Voice over Packet(VoP). In the illustrated embodiment, one or more of endpoints 22, andendpoints and components of communication networks 24 may be IPtelephony devices capable of participating in IM, video, and othermultimedia communication sessions. IP telephony devices have the abilityof encapsulating a user's voice (or other input) into IP packets so thatthe voice can be transmitted over a communication network. IP telephonydevices may include telephones, fax machines, computers runningtelephony software, nodes, gateways, wired or wireless devices, handheld PDAs, or any other device capable of performing telephony functionsover an IP network.

In particular embodiments, communication system 10 may receive andtransmit data in a session initiation protocol (SIP) environment. SIP isan application-layer control protocol that includes primitives forestablishing, modifying and terminating communication sessions. SIPworks independently of underlying transport protocols and withoutdependency on the type of session that is being established. SIP alsotransparently supports name mapping and redirection services, whichsupport personal mobility.

Although FIG. 1 illustrates a particular number and configuration ofendpoints, IS and communication networks, communication system 10contemplates any number or arrangement of such components forcommunicating media.

FIG. 2 illustrates interoperability system (IS) 50, in accordance with aparticular embodiment. IS 50 may be similar to and provide the samefunctionality as IS 20 of FIG. 1. In the illustrated embodiment, IS 50includes interface 51, gateways 52, operations management application(OMA) 54, multipoint conference system (MCS) 56, policy engine 58,authentication and security system 60, call manager 62, processor 64 andmemory module 66. IS 50 is coupled to a PC endpoint 70 that may be usedto access, configure and control various functionality provided by IS50. PC endpoint 70 may run a client application for such access,configuration and control. The client application may enable a user ofendpoint 70 to receive and monitor communications from various endpointsand virtual talk groups. In particular embodiments, other types ofendpoints may be utilized to access, configure and control IS 50, suchas IP phones, PDAs and mobile devices. IS 50 may be coupled to suchendpoints (including PC endpoint 70) through one or more communicationnetworks.

Interface 51 is used in the communication of audio, video, signaling andother data between IS 50 and other network components. For example,interface 51 may receive communications from endpoints such as endpointsof communication networks 24, endpoints 22 and endpoint 70. Thecommunication may take place over IP networks thereby negating the needfor dedicated wiring between the endpoints and the IS.

Gateways 52 may include any suitable gateways to provide networkinteroperability and back-end legacy application integration, such asLMR gateways, PSTN gateways and application gateways. Gateways 52provide mapping between IP services and the interoperable networks, suchas LMR network 24 a of FIG. 1. In some cases gateways 52 may not belocated within an IS but may be distributed throughout a communicationsystem for enabling communications among various communication networks.

Operations management application (OMA) 54 includes functionality forconfiguration, management and control of IS 50, including conference andcollaboration management, and may be accessed by a user via, forexample, PC endpoint 70. In particular embodiments, OMA 54 may enable auser, such as dispatch personnel or administrators or a mobile user(e.g., a first responder mobile user) accessing IS 50 via a mobileendpoint, the ability to configure, manage and participate in one ormore virtual talk groups and ad hoc conferences simultaneously. Inparticular embodiments, OMA 54 may be accessed through a web interface,functioning for example as a soft phone for radios. A screen display maybe controlled using a mouse, keypad, touch screen, voice commands or anyother suitable interface. OMA 54 screens may include any number offunctional controls to provide interoperable communications. OMA 54 mayauthenticate a user and obtain user configuration information upon auser accessing the OMA. OMA 54 may monitor and provide communicationability for any number of channels at one time to provide the abilityfor an OMA user to communicate on and control multiple virtual talkgroups at once.

Multipoint conference system (MCS) 56 provides collaboration andconference services for multiple endpoints of one or more networks. Forexample, users of multiple endpoints (such as LMRs of different networks(e.g., networks of different agencies or groups) and different types ofendpoints of different networks) may be bridged together through MCS 56to provide virtual talk group communications. MCS 56 may include anysuitable number or type of conference bridges, ports, digital signalprocessors or other components to facilitate communications discussedherein.

Policy engine 58 includes policies for undertaking various operationsand functionality upon the occurrence of various events to providedynamic incident management. These policies may include bothpre-determined and ad hoc policies. For example, upon the occurrence ofa particular incident, the incident may include a unique identifier andmay have basic incident attributes such as time of creation, name ofuser creating and status. A pre-determined policy may then be executedby an incident manager or dispatch personnel as action for the specificincident. In particular embodiments, policy engine may receive inputsfrom alarms and sensors to setup device agnostic communicationsinteroperability and one-way video and data collaboration and to triggeradditional events such as pagers, e-mails, notifications, dial-outs,recording and information escalation.

Authentication and security system 60 manages access, configuration andcontrol privileges for users of IS 50 and those participating ininteroperable communications. For example, different users may havedifferent privileges assigned for interoperable communications. Someusers may only have transmit or listen privileges with respect to one ormore particular talk groups, while other users may have the ability tocommunicate in all talk groups or setup and configure various talkgroups. User privileges may change dynamically upon the occurrence ofparticular events.

Call manager 62 maintains information regarding various users, such asusers of IP networks for which interoperable communications are providedby IS 50. This facilitates in the extension of PTT to IP networks and inthe provision of voice and data interoperability across radio andnon-radio networks. In particular embodiments, call manager 62 maymaintain a listing, table, or other organization of information aboutusers. The information may include a name or other identifier andcontact information such as phone numbers and email addresses for theusers. In particular embodiments call manager 62 may represent anyappropriate combination of hardware, software and/or encoded logicdistributed throughout a communication network coupled with IS.

Processor 64 may be a microprocessor, controller, or any other suitablecomputing device, resource, or combination of hardware, software and/orencoded logic operable to provide, either alone or in conjunction withother IS components such as OMA 54, IS 50 functionality. Suchfunctionality may include providing various features discussed herein toa user, such as a user of an endpoint accessing IS 50 through OMA 54.Such features may include providing to the user endpoint locationinformation of communicating endpoints of a plurality of monitoredendpoints and/or virtual talk groups, enabling the user to listen toand/or participate in communications involving endpoints and/or virtualtalk groups of a particular geographic area, presenting communicationsof endpoints of scene-related virtual talk groups according topreconfigured or received instructions and controlling various gatewaysand other network components to facilitate interoperable communicationsamong various endpoints.

Memory module 66 may be any form of volatile or non-volatile memoryincluding, without limitation, magnetic media, optical media, randomaccess memory (RAM), read-only memory (ROM), removable media, or anyother suitable local or remote memory component. Memory module 66 maystore any suitable data or information, including software and encodedlogic, utilized by IS 50. In particular embodiments, memory module 66may include data for user management, talk-group management, resourcepool management, privileges, backup configuration and information and/ortimestamp and activity tracking.

IS 50 may also include any number of switches, routers, firewalls,mobile access routers, access points, wireless bridges and othercomponents in order to accommodate particular operational desires andneeds.

In particular embodiments such as in the LMR network interoperabilitycontext, IS 50 may, through one or more components discussed above orthrough other components, encode received audio with a standard audiocodec, such as G.711 or G.729.Those audio samples may be packaged instandards-based real-time transport protocol (RTP) packets suitable fortransport on an IP network. At this point, the communication element maybe abstracted from the distinctive characteristics of each radio system.These audio packets can be sent across the network to other radiosystems either individually (unicast) or as a group (multicast). Therecipient of the audio packets may be a device capable of receiving anddecoding the RTP stream, such as an IP telephone or PC with appropriatesoftware. The IP network and IP-enabled devices can be used to allowusers to monitor or transmit on a particular radio channel from a deskwithout issuing another radio.

As indicated above, IS 50 may facilitate communication among users ofendpoints of various networks through virtual channels or talk groups.For example, a channel may comprise a unidirectional or bidirectionalpath for transmitting and/or receiving electrical or electromagneticsignals. This may comprise, for example, a conventional radio physicalRF channel. A talk group in this context may be a subgroup of users(e.g., radio users) who share a common functional responsibility andtypically coordinate actions amongst themselves without radio interfacewith other subgroups. For example, a municipality's police departmentnetwork may include various talk groups.

A virtual talk group (VTG) represents interoperability of a group ofchannels, for example, as an audio conference or meeting. A virtual talkgroup may include an associated virtual channel and an ID. Virtualchannels may comprise an address, such as an IP address, associated witha virtual talk group through which users may access the virtual talkgroup and/or through which communications from VTG member-endpoints arebridged. Various types of virtual talk groups may be utilized inparticular embodiments, such as a multicast address usable by allendpoints of the VTG, a VTG comprising multiple talk groups (e.g.,multiple radio sources from different frequencies whose communicationsare mixed), a unicast group and a combination unicast and multicastgroup.

As an example, a particular virtual talk group may comprise a conferenceor meeting of the following: (1) a channel or other multicast path usedby certain users of a police department's radio network, (2) a channelor other multicast path used by certain users of a fire department'sradio network, (3) a channel or other multicast path used by certainusers of a corporation's security radio network and (4) a plurality ofusers of IP-enabled endpoints such as IP phones, IP-enabled PDAs or PCs.An operator of IS 50 may configure the virtual talk group using anysuitable interface, such as by dragging and dropping the includedchannels and IP endpoints into a single area representing the virtualtalk group. MCS 56 may provide the functionality for the conference ofthe virtual talk group members. In particular embodiments, multiple talkgroups may be patched together on a dynamic, as needed basis. In somecases a virtual talk group may not necessarily include communicationsthrough an IS but may instead include member endpoints whosecommunications are mapped to IP addresses at gateways (such as LMRgateways) controlled by an IS.

Any number of virtual talk groups may be configured to provide anysuitable audio, data, video and control network interoperability.Virtual talk groups may be created using any suitable user/endpointgroups or channels based on location, organizational requirements, eventrequirements or any other suitable characteristic. An administrator oroperator may configure channel details such as name, description,participants, multicast IP addresses, codec and latch options through,for example, OMA 54.

FIG. 3 illustrates an endpoint 80, which may comprise a mobile endpoint,in accordance with a particular embodiment. Endpoint 80 may be similarto, and may provide similar functionality to, other endpoints discussedherein.

In the illustrated embodiment, endpoint 80 includes atransmitter/receiver 82, a user interface 84, a processor 86 and amemory module 88. Transmitter/receiver 82 obtains signals from GPSsatellites or ground stations of a communication network in order todetermine a position of endpoint 80 and also receives and transmitscommunications such as audio, video and other data to and from othernetwork components. User interface 84 provides a mechanism through whicha user of endpoint 80 may operate the endpoint and communicate withother network devices. Interface 84 may comprise a keypad, display,touch screen, audio input or any other suitable interface. Instructionsmay be submitted through speech recognition, collection of keystrokes,soft key or otherwise.

Processor 86 may be a microprocessor, controller, or any other suitablecomputing device, resource, or combination of hardware, software and/orencoded logic operable to perform endpoint functionality. Processor 86,either alone or in conjunction with other endpoint components, providesendpoint functionality discussed herein. Memory module 88 may be anyform of volatile or non-volatile memory including, without limitation,magnetic media, optical media, random access memory (RAM), read-onlymemory (ROM), removable media, or any other suitable local or remotememory component.

In particular embodiments, communications from endpoints such asendpoint 80 may include GPS information indicating the location of theendpoint from which a particular communication is transmitted. The GPSinformation may be carried by both unicast and multicast communications.With this information, whenever a user utilizes an endpoint tocommunicate, the specific location from where the media (e.g., PTT orother communication) was transmitted may be identified, for example atPC endpoint 70 through IS 50. In some cases, a gateway may be used tobridge between media streams that include location information of atransmitting endpoint and media streams that do not include locationinformation of a transmitting endpoint. For example, some legacy mobiledevices may not be able to embed or otherwise include GPS informationwithin a media stream.

In particular embodiments, endpoint 80 may be used by a command officeror other user and may run a client application of IS 50. In some casesendpoint 80 may receive communications from a plurality of endpoints,and processor 86 may filter out certain communications for presentationto a user of endpoint 80 based on the location of the transmittingendpoints of the communications. As discussed herein, communicationsreceived may include GPS or other location information identifyinglocations of their transmitting endpoints.

As discussed above, particular embodiments provide the ability totransport geographical location information from mobile endpoints toeach other and to an IS and the utilization of this information fordisplaying the location (e.g., as a street or block number within a cityor in another manner) to other users, as well as presenting an iconassociated with the specific mobile endpoint and with its location. Insome embodiments GPS information may be appended to a multicast streamin a header of a packet transmission or to a unicast stream. GPSinformation may be carried by being steganographically embedded within avoice stream or in the header of IP packets. With the locationinformation, whenever an end-user at a mobile station talks, rather thansimply having an indicator show the VTG of the last communication, anicon or other indicator (e.g., on a map) may show the specific locationfrom where the media (e.g., PTT media) arrived. In some cases, specialattention may be given to conferencing when more than one speaker talkswhen, for example, SIP and unicast may be used. In this case theplurality of location information from all talkers may be embeddedwithin the media stream, and all icons of all speakers may blink toindicate where the speakers are located. Particular embodiments alsoprovide backwards compatibility to existing systems. For example, when aspeaker from an unknown location speaks, the system may indicate the VTGover which the voice came, but the location of that speaker may not bepresented on the map.

Furthermore, particular embodiments provide the ability of an endpointsuch as endpoint 80 to filter communications presented to its user basedon the location of transmitting endpoints of the communications. Forexample, an endpoint used by personnel monitoring a plurality ofinteroperable communications facilitated by an IS (such as endpoint 80running a client application of IS 50) may receive many media streamsfrom a variety of VTGs. The endpoint may present to its user only themedia streams that originate from within a pre-defined neighborhood. Asdiscussed above, communications may include GPS information oftransmitting endpoints appended to multicast and/or unicast mediastreams. In some cases the user may draw an area of interest on a map,and the communications that originate with the area may be filtered forpresentation to the user. For example, when a supervisor wants to listento activities from a specific site, he can click on that area of the mapand/or highlight a specific area on the map and select a “listen” or“participate” function. As discussed above, in one embodiment the filtersteps may be performed at the user's endpoint. In some embodiments, thefilter may be generated at an IS and downloaded to the relevantendpoint. This allows the filter to be stored and managed from a centralIS. In some embodiments a user such as a policeman may want to obtaininformation from sensors in his area of interest. In this embodiment,GPS information may be embedded in the information stream from thespecific sensors. In some cases, as the system establishes a conferenceof users or a VTG, the location information is used in the speakerselection algorithm. For example, in accordance with one embodiment, asthe system selects the top three speakers, the speakers who are closestto the center of the event are given priority over users who are fartheraway from the center of the event.

Moreover, particular embodiments provide automated configuration ofendpoints into VTGs based on their locations. GPS information isappended to multicast and/or unicast media streams. In one embodiment, auser through a client application may establish connection with an IS,such as IS 50, and may continuously update the IS regarding the user'slocation. Using GPS source location, the IS may configure endpoints asparticipants in a VTG that spans their neighborhood. In someembodiments, the neighborhood may be defined by a configurable distancefrom an event or as all endpoints who are in proximity to the user(e.g., within 4 miles from the user). In other embodiments, theneighborhood may be defined by drawing an area on a map on the user'sendpoint display. By defining the area of the neighborhood, the clientapplication user's endpoint may be automatically joined into a VTG withall users whose locations fall within the defined neighborhood. Inaddition, participant endpoints in the VTG may dynamically change (e.g.,may be added and removed from the VTG) since the endpoints may be mobileand their locations may continuously change.

In some cases, the IS may apply hysteresis. As a result, once a userjoins the geographically defined VTG he may remain a member through theend of the event. In some cases, hysteresis may be utilized based on anarea. For example, one a user is automatically added to a geographicallydefined VTG based on the user's location within a first area, the usermay remain a member of the VTG despite leaving the first area as long asthe user is within a second, larger area that includes the first area.Hysteresis may be applied to any of the functionality discussed herein,including the mere receipt of communications from endpoints within aparticular area. In some cases, a user may elect to opt out of the VTGif he travels out of the area defined by the system as the eventlocation area. Embodiments may automatically conference users who arejoining the VTG via unicast with, e.g., SIP signaling. Some embodimentsmay also automatically and dynamically add and drop users into/from aconference bridge using hysteresis as a key part of an add/drop useralgorithm. In one embodiment, users of endpoints may be requested toapprove the automatic action of dropping them out of the VTG. In somecases, a user traveling through different areas may be coming in and outof multicast range. An IS in some embodiments may automatically switchthe user between multicast connectivity and a nailed SIP connection toaccommodate capabilities of a locally available network. In addition, insome cases if a user is continuously moving in and out of a multicastarea, the IS may fix their connectivity to a VTG via a nailed dialedconnection.

FIG. 4 is an example display 200 of an endpoint, such as PC endpoint 70or another mobile or non-mobile endpoint, accessing IS 50 through OMA54, in accordance with a particular embodiment. In the illustratedembodiment, display 200 includes location portion 202 and VTG controlportion 204; however, it should be understood that displays of endpointsaccessing IS 50 in other embodiments may include additional or differentinformation related to functionality of IS 50 and communicationsfacilitated therethrough.

In this embodiment, location portion 202 displays a particulargeographical area showing multiple mobile endpoints 210 a-210 c, 212a-212 c and 214 a-214 c.VTG control portion 204 shows three virtual talkgroups (1, 2 and 3), each comprising a plurality of members. Forexample, VTG 1 comprises endpoints 210 a-210 c;VTG 2 comprises endpoints212 a-212 c;and VTG 3 comprises endpoints 214 a-214 c.As discussedabove, particular endpoints of various networks (e.g., various publicsafety agency networks) may be grouped together in virtual talk groupsaccording to any number of factors. In the illustrated embodiment,endpoints 212 a, 212 b and 212 c make up VTG 2 and are associated withincident 213, which may comprise a burglary, fire or other incident. Forexample, if incident 213 is a fire, a user of endpoint 212 a may be acity police officer and endpoint 212 a may be part of that city's policedepartment network. A user of endpoint 212 b may be fire departmentpersonnel responding to the fire, and endpoint 212 b may typicallycommunicate on a different fire department network. As also illustrated,endpoints 214 a, 214 b and 214 c form VTG 3 and are associated withincident 215.

As discussed, endpoints of each VTG may be a part of different networks,such as different radio networks of different public or private agenciesor groups. For example, with respect to VTG 1, endpoint 210 a may be aland mobile radio of a police officer from a particular municipalitypolice network, endpoint 210 b may be a land mobile radio of a policeofficer from a different municipality police network and endpoint 210 cmay be a cellular phone of a federal agency network. As discussed above,IS 50, through Internet Protocol, enables various endpoints of differentnetworks to communicate in talk groups using the technology of suchnetworks. For example, communications among endpoints 210 a-210 c mayuse PTT technology and may be facilitated by IS 50.

A user such as a command officer or dispatch personnel may use display200 to monitor communications of various channels or talk groups, suchas various talk groups composed of land mobile radio or other endpointusers. For example, a command officer may use display 200 to monitorcommunications on VTGs 1, 2 and 3. Whenever a particular mobile endpoint210, 212 or 214 user communicates through the endpoint, such as when auser communicates a PTT audio message, the endpoint of display 200(e.g., PC endpoint 70) may communicate the transmission through the PCendpoint. As indicated above, communications transmitted from a mobileendpoint may comprise audio, video or other data (including PTTmessages, IMs, e-mails, streaming video, etc.). Display 200 indicatesfrom which VTG and/or mobile endpoint the communication is transmitted.The communication from the mobile endpoint may also include locationinformation (e.g., GPS information) identifying the location of themobile endpoint transmitting the message. IS 50 may receive thislocation information and present to the command officer the location ofthe mobile endpoint as it communicates the actual message from theendpoint.

For example, assume in the illustrated example that mobile endpoint 212a is a police officer's land mobile radio and that its police officeruser is communicating an audio message to other members of VTG 2. Theseother members may include, for example, users of endpoints 212 b and 212c as well as all other users, such as administrative, command ordispatch users, that have access privileges to receive communications ofmembers of this virtual talk group. When transmitting the audio message,endpoint 212 a also transmits information identifying its location. Thismessage may be communicated through a base station and other componentsof one or more communication networks and received at IS 50. IS 50 thencommunicates the message to other endpoints of the talk group (e.g.,endpoints 212 b and 212 c) if such endpoints are not a part of the sameradio network as endpoint 212 a.In addition, when communicating theaudio message from endpoint 212 a, IS 50 may communicate the locationinformation identifying the location of endpoint 212 a.Thus, a user ofan endpoint presenting display 200 using the endpoint and associateddisplay to monitor communications on VTGs 1, 2 and 3 will know thelocation of endpoint 212 a as the user receives communications from theendpoint.

The communication of the particular VTG or endpoint identification of aparticular communication as well as the endpoint's location may beperformed in any of a variety of ways according to particularoperational needs and desires. As an example, in display 200 aparticular endpoint transmitting a message communicated to a user of IS50 may be highlighted or otherwise identified in VTG control portion204. In addition, the associated VTG number may be highlighted orotherwise identified as well. Moreover, as indicated, as the endpoint ofdisplay 200 transmits the audio message from endpoint 212 a, display 200may highlight endpoint 212 a (as illustrated) and may identify theparticular endpoint's location, such as identifying a street addresslocation of the endpoint (as illustrated).

The illustrated example shows locations of various endpoints 210, 212and 214. In some cases, the locations of these endpoints may be updatedwhen a user of the endpoint transmits an audio, video or other messagethrough the endpoint since location information may be transmitted atthat time (e.g., embedded within the media stream).

As indicated above, display 200 is only one example of communicatinginformation as described herein, and other embodiments may communicateendpoint location information of communicating endpoints of variousnetworks and talk groups in any suitable manner. Endpoint locationinformation may be transmitted with endpoint communications in anysuitable manner, such as through GPRS or steganographically. Inparticular cases, the communications from mobile endpoints comprisemulticast communications that are transmitted to other endpoints of thesame network and to IS 50 for transmission to endpoints of othernetworks. In some embodiments, location information and other metainformation, such as unit ID, priority and channel, may be communicatedusing a separate associated multicast port/channel.

In some cases, location information may be transported in a real-timetransport protocol (RTP) header extension. For example, RTP headersinclude a reserved area in the header to put a variable length headerextension that could contain additional information about an RTP talker.As another example, location information may be transported using thereal-time control protocol (RTCP) stream. The RTCP port is one higherthan the RTP port by definition. In particular cases, other attributesabout the endpoint may already be included using RTCP. The locationinformation may comprise, for example, GPS latitude/longitudeinformation or street and/or city information. In some embodiments, theassociated RTP stream may include the location information. As anexample, 239.1.1.1:21111 might be a RTP multicast address:port throughwhich the voice stream is transported, and another address:port (forexample, the RTP VOIP port+2 for the RTP signaling port) may be used toinclude the location information.

In particular embodiments, the location information may be communicatedto all original streams, such as via multipoint conference system 56 ofIS 50 or directly between the endpoints without traversing through theIS. For example, GPS1, GPS2 and GPS3 may comprise GPS information fromthree separate endpoints involved in a talk group. In the case of theappended RTP header example, the multipoint conference system maycombine and/or append the meta data components at the point of themixing or bridging function. In the case of the separate control channelexample, the streams may flow to all application aware endpoints, and anendpoint may recognize and determine the interesting or relevant GPSinformation from multiple meta streams. In the case of the RTCP modelexample, RTCP streams may be typically collected and terminated at eachendpoint. Multipoint conference system 56 may terminate the RTCP metainformation and regenerate an associated RTCP stream on the other sidefor transmission to endpoints of the virtual talk group. In some cases,either the RTP header extension or a new payload type may be used. Inparticular cases, a description field may be used. In a situation whereMCS 56 mixes more than one media stream, the location description fieldmay include the locations of a plurality of speaking endpoints. The RTPheader may be sent for every packet and may be large overhead but may bebest for real time changing information. The particular data,application and operational requirements and desires may dictate thebest methodology for transmission of the location information.

FIG. 5 is an example display 300 of an endpoint 302 which may comprise amobile or non-mobile endpoint, in accordance with a particularembodiment. Display 300 also includes endpoints 304, 306, 308, 310, 312,314 and 316, which may comprise any type of mobile or non-mobileendpoints of one or more communication networks, such as endpoints andcommunication networks described above. When transmittingcommunications, endpoints 304, 306, 308, 310, 312, 314 and 316 mayinclude GPS information identifying their locations in a similar manneras discussed above with respect to FIGS. 3 and 4.

Some of the illustrated endpoints are members of virtual talk groupsconfigured through IS 50. Table 301 lists virtual talk groups 1-5 andcurrent endpoint members of each such VTG. For example, VTG 1 includesendpoints 304 a-304 e, VTG 2 includes endpoints 306 a-306 b, VTG 3includes endpoints 308 a-308 c, VTG 4 includes endpoints 310 a-310 e andVTG 5 includes endpoints 316 a-316 f.Currently, endpoints 312 and 314are not included in any VTG of the IS.

Endpoints 304, 306, 308, 310 and 316 may be assigned a VTG for anyoperational need, such as geography and/or event or incident. Forexample, endpoints 316 a-316 f may be grouped into a VTG (e.g., VTG 5)to respond to a particular incident. The incident may have occurred, forexample, proximate endpoints 316 a, 316 d, 316 e and 316 f. Whileendpoints 316 b and 316 c are not currently in the immediate vicinity ofthe incident, it may be desired, for any particular reason, to includethose endpoints so that they can participate in the VTG communications.

The endpoints illustrated on display 300 may be part of differentcommunication networks. For example, endpoint 310 a may be a mobileendpoint of a police department network that communicates on aparticular radio frequency, and endpoint 310 d may be a mobile endpointof an ambulance service network that communicates on a different radiofrequency. In some cases, endpoints of different communication networksmay include endpoints that are communicating on different channels orfrequencies (e.g., one endpoint may be communicating on a frequencyreserved for police department A while another endpoint may becommunicating on a frequency reserved for fire department B). IS 50facilitates interoperable communications among such endpoints such thatcommunications transmitted by endpoint 310 a may be communicated,through one or more base stations or other network components, toendpoint 310 d.In addition, IS 50 may convert communications receivedfrom these endpoints to IP packets for transmission and receipt byparticular IP endpoints which may include, for example, other endpoints310 of talk group 4 as well as command personnel accessing IS 50 throughOMA 54. In some cases, IS 50 may control various gateways to facilitatethe conversion of communications to IP packets.

Particular embodiments enable a user to listen, participate or otherwisecommunicate with particular endpoints or VTGs according to location. Asindicated above, endpoint 302 presents display 300 to a user such as acommand officer or dispatch personnel. In particular embodiments, such auser may configure endpoint 302 to listen to discussions or otherwisereceiving communications in a particular geographical area of display300. Such area may include any suitable geographical area identified bythe user, such as an area within a particular radius of the currentlocation of endpoint 302 or another area that does not include thecurrent location of endpoint 302. For example, in some cases when a userof endpoint 302 desires to listen to activities from a particular site,the user may click on a particular area of the display map presentedand/or highlight a specific area of the map and select a “listen” or“participate” function. As a result, IS 50 may automatically configurethe user's endpoint to be a part of the VTGs active in this geographicalarea. The interface through which a user may identify and select aparticular area may comprise any suitable interface according tooperational needs and desires, such as a mouse, touch screen, key pad oraudio command. In particular embodiments, a user may zoom in or out on aparticular display to identify and select a geographical area ofparticular virtual talk groups or endpoints. In some cases, a displaymay be partitioned into multiple segments or portions for selection by auser.

As an example, a user of endpoint 302 may select a particular distancefrom endpoint 302 that defines a geographical area 320 so that the userof endpoint may be presented (by his endpoint) with communications fromall endpoints included within this area, including VTGs that includeendpoints within this area. Thus, in the illustrated embodiment, a userof endpoint 302 could listen to or communicate with endpoints 304 b, 304e, 310 b, 310 d, 310 e, 312, 316 b and 316 c.Endpoint 302 may receiveGPS information from endpoints identifying their location to determinewhether the endpoints are within area 320 such that their communicationsshould be presented to its user. Endpoint 302 may receive communicationsfrom, for example, all endpoints of the display but may filter orotherwise select communications from endpoints within the selected areafor presentation to its user. Such presentation may be made through, forexample, a speaker, display or other interface. In some embodiments, apolicy engine of an IS may store pre-defined areas of interest that areinvoked as part of a specific policy.

It should be understood that since endpoints 304 b and 304 e are part ofVTG 1, endpoints 310 b, 310 d, and 310 e are part of VTG 4 and endpoints316 b and 316 c are part of VTG 5, in some cases the user of endpoint302 may be able to communicate with endpoints of VTGs 1, 4 and 5 notincluded within geographical area 320. For example, assume endpoints 304a and 304 b are a part of the same LMR network such that theycommunicate on the same radio frequency. To allow endpoint 302 tocommunicate with endpoint 304 b (since endpoint 304 b is within area320), IS 50 would have to receive communications from endpoint 302 andtransmit the communications to endpoint 304 a on the applicable radiofrequency that endpoint 304 b may also be able to receive.

In particular cases, endpoint 302 may be a mobile endpoint such thatwhen it moves, area 320 moves since area 320 is defined by a particulardistance from endpoint 302. For example, if endpoint 302 moves eastward,then endpoint 304 b, if stationary, may no longer be within area 320such that a user of endpoint 302 may no longer be able to communicatewith endpoint 304 b according to this criteria.

As another example, a user of endpoint 302 may select a geographicalarea to communicate with that does not include the present location ofendpoint 302. For example, a user of endpoint 302 may identify andselect area 330. Endpoint 302 may then determine, based on GPSinformation received, that endpoints 310 a and 310 c and endpoints 316a, 316 d, 316 e and 316 f are presently within area 330 and may ensurethat the user of endpoint 302 is presented communications from suchendpoints. In some cases, endpoint 302 may present all communicationsreceived by those endpoints within area 330. For example, endpoints 310a and 310 c communicate in VTG 4 and may thus receive communicationsfrom other members of the VTG, such as endpoints 310 b, 310 d and 310e.If a user of endpoint 302 is configured to receive communicationsreceived by all endpoints within area 330, then the user may alsoreceive communications from, for example, endpoint 310 b since VTG 4communications from this endpoint will be received by endpoint 310 awhich is within area 330.

In particular embodiments, in response to the selection of ageographical area, a virtual talk group comprising all endpointscurrently in that area may be formed. As such endpoints leave the area,they may be removed from the VTG. Similarly, as other endpoints enterthe selected area, they may be added to the VTG. In this manner, VTGsmay be created based on location of endpoints. In some cases, onlycertain types of endpoints (e.g., such as only public security agencyendpoints) may be added to a VTG defined by endpoints of a particulargeographical area.

As discussed above, in particular embodiments a mobile endpoint mayfilter received communication streams according to the location fromwhich the streams are transmitted. This may be accomplished, forexample, when the media streams include the GPS or other locationinformation of the transmitting endpoint. For example, a mobile endpointsuch as endpoint 304 b may receive all communications from each endpointin VTG 1. Each such communication may include GPS informationidentifying the location of the communication's source endpoint.Endpoint 304 b may include a processor, similar to that described abovewith respect to an IS, that filters out for communication to a user ofendpoint 304 b only those communications received from endpoints in aselected or predefined geographical area. Such geographical area may beselected and/or predefined by a user of endpoint 304 b in a similarmanners as in other embodiments described above with respect to endpoint302. Thus, even though the endpoint may receive communications fromvarious locations, the endpoint may examine the GPS information in suchcommunications to play or otherwise present to its user only thosecommunications coming from a particular location, region or area. Whilesome embodiments discussed above discuss location information or GPSinformation filter functionality at an endpoint, it should be understoodthat this filter functionality may be performed at an IS and selected orfiltered communications may then be transmitted to a user's endpoint forpresentation to the user.

FIG. 6 is an example display 400 of an endpoint 420 which may comprise amobile or non-mobile endpoint accessing IS 50 through OMA 54, inaccordance with a particular embodiment. Display 400 also showsendpoints 402 a-402 d, 404 a-404 e, and 410 a-410 c, which may compriseany type of mobile or non-mobile endpoints of one or more communicationnetworks, such as endpoints and communication networks described above.In addition, display 400 shows hospital network 406 and police stationnetwork 408 which each include one or more endpoints at the hospital andpolice station, respectively. When transmitting communications, theillustrated endpoints may include GPS information identifying theirlocations in a similar manner as discussed above.

Illustrated endpoints are members of virtual talk groups configuredthrough IS 50. Table 401 lists virtual talk groups 1-4 and currentendpoint members of each such VTG. For example, VTG 1 includes endpoints402 a-402 d and hospital 406, VTG 2 includes endpoints 404 a-404 e andpolice station 408, VTG 3 includes endpoints 410 a-410 c and VTG 4includes hospital 406. As discussed above, endpoints in particularembodiments may be assigned a VTG for any operational need, such asgeography, scene or event or incident. As used herein, the terms scene,event or incident can be used interchangeably to describe one another.For example, a scene may include an event or incident. In this example,VTG 1 is associated with a scene 403, VTG 2 is associated with a scene405, VTG 3 is associated with a scene 411 and VTG 4 is associated withhospital scene 406 which, as discussed above, includes one or morehospital endpoints. The endpoints illustrated on display 400, includinghospital 406 and police station 408, may be part of differentcommunication networks. Such different communication networks mayinclude different LMR networks, LANs, cellular networks or any othertype of communication network as discussed herein.

In particular embodiments, a user's endpoint may be configured tolisten, participate or otherwise communicate with particular endpointsor VTGs according to scene, incident or event. As indicated above,endpoint 420 presents display 400 to a user such as a command officer ordispatch personnel. In particular embodiments, such a user may configureendpoint 420 to listen to discussions or otherwise receivecommunications according to a particular scene using any suitablecriteria or instructions. Configuration instructions may be received byan interface of IS 50 from a user through an endpoint interface or froma system operator, administrator or other personnel. In some cases, auser's endpoint may be preconfigured to listen to particularscene-related VTGs according to any suitable set of preconfigurationinstructions.

As an example, assume that a user of endpoint 420 is a police commandofficer currently communicating on VTG 1 associated with a car accidentscene 403. VTG 1 includes endpoints 402 a-402 d and hospital 406. Assumethat scene 405 comprises a burglary and that the police command officerusing endpoint needs to drive to the burglary scene. As indicated above,VTG 2 is associated with scene 405 and includes endpoints 404 a-404 eand police station 408. In particular embodiments, endpoint 420 isconfigured to automatically switch to VTG 2 of burglary scene 405 asendpoint 420 gets close to the scene. In some cases, endpoint 420 mayswitch to one or more VTGs of the closest scene to endpoint 420. Forexample, when endpoint 420 becomes closer to scene 405 than scene 403,the endpoint may switch to VTG 2. Similarly, if endpoint 420 was closestto scene 411, it would switch to VTG 3.

As another example, assume that a user of endpoint 420 is an ambulancedriver at car accident scene 403. Endpoint 420 may thus be patched intoVTG 1 associated with scene 403. The ambulance driver may need to take avictim of the accident to hospital 406. As indicated above, endpoints ofhospital 406 may also be a part of another group, VTG 4, associated withthe hospital. As endpoint 420 gets closer to hospital 406, the endpointmay be configured to automatically switch to VTG 4. This may be donebecause the driver may no longer need to speak with members of VTG 1since he has left scene 403. Switching to VTG 4 which just includeshospital endpoints 406 may reduce unnecessary information flow to theambulance driver and help him focus on delivering the patient promptlyto the hospital. By removing communications from VTG members at thescene of the accident, overflow of irrelevant information to the driveris reduced and the driver is allowed to focus on hospital-specificinformation.

Instead of switching to a VTG associated with a closest scene, in somecases an endpoint 420 may be configured to switch to one or more VTGs ofscenes within a particular distance of the endpoint. Thus, the endpointmay receive communications from a plurality of VTGs associated with aplurality of scenes. GPS information received by endpoint 302 may beused by IS 50 to determine the location of endpoint 302 and thereforethe proper VTG(s) in which endpoint 302 would participate based onsuitable instructions.

Endpoints may be configured to switch to VTGs of particular scenesaccording to any suitable criteria or instructions. In some cases,endpoint 302 may be configured to switch to all VTGs associated withscenes, events or incidents of a particular priority level. For example,if scenes 403, 405 and 411 comprised a hostage crisis, an armed robberyand a car accident, respectively, scenes 403 and 405 may be assigned ahigher priority than scene 411. As such, endpoint 420 may be configuredto automatically participate in VTGs 1 and 2 (associated with scenes 403and 405). Various priority levels may be assigned to scenes inaccordance with particular needs. In addition, endpoint 420 mayautomatically switch to various VTGs dynamically as scenes, events andincidents occur in a similar manner as the switching of endpoint 420 toVTGs based on location.

As another example, in some cases endpoint 420 may be configured toswitch to all VTGs associated with scenes, events or incidents of aparticular type. For example, VTGs may exist for various types ofincidents, such as police incidents, fire incidents, rescue incidents,federal incidents, investigation incidents and private organizationincidents. In some cases, endpoint 302 may be configured to listen toall police incidents as they arise. In some cases, endpoint 420 may beconfigured to listen to all burglary scenes or all hostage scenes or allfire scenes or all car accidents as they arise. In other cases, a userof endpoint 420 may comprise a company security officer whose endpoint420 automatically listens to all VTGs associated with security-relatedincidents. In some embodiments, the selection of scenes (e.g., bypriority, type or other characteristic) may be combined with aparticular geographical area. For example, endpoint 420 may beconfigured to listen to all high priority scenes in a particulargeographic area or all car accident scenes in a particular area.Particular embodiments may enable an endpoint to be configured to listento and/or communication with any of a variety of event, incident orscene-specific virtual talk groups according to any of a variety offactors, characteristics, or criteria. For example, a chief of police ofWashington, D.C. may always be tuned into any communication originatingfrom the vicinity of the White House.

As indicated above, endpoints whose communications are facilitated by anIS may include PTT endpoints. Since PTT endpoints are typically halfduplex devices, one must “control the floor” in order to talk to otherendpoints in a talk group. Particular embodiments may selectivelyprovide floor control to an endpoint requesting to talk based on thedistance of the endpoint to an incident or scene associated with avirtual talk group, particularly if more than one PTT endpoints isrequesting to talk at the same time. For example, an IS may give floorcontrol to the endpoint requesting to talk that is closest to an eventassociated with a VTG of which the endpoints requesting to talk aremembers. As is the case in other embodiments, the IS may analyzelocation information transmitted in communications or in the actual talkrequest control signal from the endpoints.

It will be recognized by those of ordinary skill in the art thatendpoints and interoperability systems disclosed herein are merelyexample configurations in accordance with particular embodiments. Thesesystems may include any number of interfaces, processors, memorymodules, and other components to accomplish the functionality andfeatures described herein. In addition, these components and otherdesired components for performing the above described functionality maybe centrally located (local) with respect to one another, or distributedthroughout communication systems and networks. In addition, one or morecomponents of these systems and devices may work together in performingvarious functionality described herein.

FIG. 7 is a flowchart illustrating a method for providing interoperablecommunications with location information, in accordance with aparticular embodiment. The method begins at step 500 wherecommunications from a plurality of virtual talk groups are received. Thevirtual talk groups may each comprise a plurality of endpoints ofdifferent communication networks. It should be understood that forpurposes of the descriptions and claims herein, whenever a VTG isdescribed as comprising a plurality of endpoints of differentcommunication networks, in addition to including at least some endpointsof different communication networks, the VTG may also include someendpoints of the same communication network. For example, the VTG mayinclude a plurality of endpoints of the same police department networkin addition to one or more endpoints of other communication networks,such as other police or fire department or private company networks.Moreover, in some cases, endpoints of different communication networksmay include endpoints that are communicating on different channels orfrequencies. The different communication networks may comprise networksof different technologies, such as IP, cellular, PSTN, LMR, CDMA, GSM,TDMA, GPRS and satellite. In particular embodiments, at least some ofthe endpoints of the virtual talk groups may communicate through PTTtechnology. In addition, some of the endpoints may comprise IPendpoints. Moreover, the different communication networks may comprisenetworks of various safety and security agencies, whether public orprivate as well as networks of public and private groups, companies ororganizations. The communications may be received at an interoperabilitysystem and/or at a client application of an interoperability system.

The communications may be received via a multicast stream whose headerincludes the location information or via a unicast stream with thelocation information. The virtual talk groups may include communications(from the various endpoints) that are facilitated by an IS by mappingthe communications to a multicast IP address or by bridging thecommunications at a multipoint conference system of the IS.

At step 502, a first communication is received from a first mobileendpoint of a first virtual talk group of the plurality of virtual talkgroups. The first communication comprises a first media message andlocation information identifying a location of the first mobileendpoint. The location information may comprise GPS information. Themessage may comprise an audio, video, IM or other data message from thefirst endpoint, such as a push-to-talk communication from a land mobileradio.

At step 504, the first media message is presented to a user. At step506, an identification of the first virtual talk group may be presentedto the user. At step 508, the location of the first mobile endpoint ispresented to the user. The user may be receiving communication fromendpoints of the monitored plurality of virtual talk groups, forexample, through a PC, IP phone or other endpoint running a clientapplication that accesses an IS. As the first message from the firstmobile endpoint is presented to the user, an identification of the firstvirtual talk group of which the first mobile endpoint is a member may betransmitted to the user by an IS. This may aid a user who is presentedinformation from multiple virtual talk groups to determine from whichvirtual talk group the first communication is transmitted. In addition,the location of the first mobile endpoint may be presented to the userby the IS. Such presentation of the first virtual talk groupidentification and location of the first mobile endpoint may be througha display of an endpoint through which the user accesses the IS usingany suitable presentation method. In some embodiments, the location ofthe first mobile endpoint may be presented as a geographical address,such as a street address or longitude and latitude or other coordinateaddress.

FIG. 8 is a flowchart illustrating a method for communicating mediabased on location of media source, in accordance with a particularembodiment. The method begins at step 600 where communicationscomprising a media message and location information are received from aplurality of endpoints. The communications may be received at a user'smobile endpoint. In some cases an IS may facilitate the transmittal ofthe communications to the endpoint, such as by controlling LMR gatewaysor other components, by mapping communications to a multicast IPaddress, by bridging communications into a mixed stream or by othermethods. In some cases the communications may be received from endpointsof different virtual talk groups. The communications may be received viamulticast streams or nailed dialed connections, such as those using SIPprotocol. In particular embodiments, at least some of the transmittingendpoints may communicate through PTT technology. In addition, some ofthe endpoints may comprise IP endpoints. The location informationidentifies a location of the endpoint communicating the message and maycomprise GPS information.

At step 602, a selection of a geographical area is received from a user.The user may be a command officer or other user utilizing a mobileendpoint. The selection of a geographical area may be received by theuser, for example, selecting the area on a display of his endpoint suchas by drawing the area on a map shown on a touch screen display.

At step 604, location information of each communication is compared withthe selected geographical area. Such comparison may be performed at theuser's mobile endpoint. As indicated above, the location informationidentifies a location of the endpoint transmitting the communication. Atstep 606, the endpoint determines whether the location information ofeach transmitting endpoint is within the selected geographic area. Foreach endpoint whose location information indicates that the transmittingendpoint is not in the selected geographic area, the method ends.However, the method may continue to check whether other endpoints moveinto the selected geographic area or whether endpoints not in the areacome to be within the area as a result of the area moving.

At step 608, for each transmitting endpoint whose location informationindicates that the endpoint is within the selected geographic area, eachmessage from each such endpoint is presented to the user by, forexample, the user's endpoint. These messages may be communicated to theuser through a display, speaker or other audio interface. The messagesmay comprise push-to-talk messages received from LMR endpoints withinthe selected geographic area. In particular embodiments, communicationsfrom the plurality of endpoints may be presented to the user as long asthe various endpoints are within the geographical area. In addition, asother endpoints enter the selected geographical area, theircommunications may be presented to the user as well. Thus, someembodiments may send an audio stream to a user that mixes communicationsfrom all endpoints currently within an area, and the mixed stream mayaccount for and dynamically include (and exclude) communications fromendpoints as they enter and leave the area.

FIG. 9 is a flowchart illustrating a method for automatic configurationof virtual talk groups based on location of media source, in accordancewith a particular embodiment. The method begins at step 700 wherecommunications from a plurality of endpoints are monitored, such as atan interoperability system. Each communication may comprise a mediamessage and location information identifying a location of itstransmitting endpoint. At step 702, virtual talk group configurationinstructions based on the locations of the mobile endpoints arereceived. In some cases virtual talk group configuration instructionsmay be received from a user accessing an OMA 54 of an IS through an ISclient application. In some cases virtual talk group configurationinstructions may be pre-loaded or pre-configured on the IS.

The virtual talk group configuration instructions may include, forexample, instructions to configure a virtual talk group of mobileendpoints within a first distance of an event (e.g., a car accident,burglary, terrorist or other event), within a first distance of aparticular user's mobile endpoint (e.g., such as a user accessing an ISthrough a client application) or within a geographic area selected on amap by a user. Virtual talk group instructions based on locations ofmobile endpoints may include instructions to configure the virtual talkgroup based on any of a variety of suitable or desired operationalfactors or characteristics.

At step 704, a first group of mobile endpoints is selected according tothe virtual talk group configuration instructions. For example, if thevirtual talk group configuration instructions include instructions toconfigure a virtual talk group of all mobile endpoints within aparticular distance of an event, then all such endpoint may be selectedat step 704. At step 706, a first virtual talk group comprising theselected first group of mobile endpoints is configured to facilitatecommunications among the selected first group of mobile endpoints. Theselected first group of mobile endpoints may include mobile endpoints ofdifferent communication networks. The communications among members ofthe virtual talk group may be facilitated by an IS by, for example,controlling LMR and other gateways coupling various types ofcommunication networks. In some cases the communications may be mappedto one or more multicast IP addresses to enable the virtual talk group.In some cases communications from the various endpoints may be bridgedby a multipoint conference system into a communication stream fortransmission to endpoints of the virtual talk group.

As in other embodiments, a virtual talk group may comprise endpointsutilizing different technologies. In particular embodiments, at leastsome of the endpoints may communicate through PTT technology. Inaddition, some of the endpoints may comprise IP endpoints. Moreover, thedifferent communication networks may comprise networks of various safetyand security agencies, whether public or private as well as networks ofpublic and private groups, companies or organizations.

Some of the steps illustrated in FIGS. 7, 8 and 9 may be combined,modified or deleted where appropriate, and additional steps may also beadded to the flowcharts. Additionally, steps may be performed in anysuitable order without departing from the scope of the invention.

While various implementations and features are discussed with respect tomultiple embodiments, it should be understood that such implementationsand features may be combined in various embodiments. For example,features and functionality discussed with respect to a particular figuresuch as one of FIGS. 4-9 may be used in connection with features andfunctionality discussed with respect to another such figure according tooperational needs or desires.

Although the present invention has been described in detail withreference to particular embodiments, it should be understood thatvarious other changes, substitutions, and alterations may be made heretowithout departing from the spirit and scope of the present invention.For example, although the present invention has been described withreference to a number of elements included within communication system10 and illustrated endpoints and interoperability systems, theseelements may be combined, rearranged or positioned in order toaccommodate particular routing architectures or needs. In addition, anyof these elements may be provided as separate external components tocommunication system 10 and illustrated endpoints and interoperabilitysystems, or each other where appropriate. The present inventioncontemplates great flexibility in the arrangement of these elements aswell as their internal components.

Numerous other changes, substitutions, variations, alterations andmodifications may be ascertained by those skilled in the art and it isintended that the present invention encompass all such changes,substitutions, variations, alterations and modifications as fallingwithin the spirit and scope of the appended claims.

1. A method for automatic configuration of virtual talk groups based onlocation of media source, comprising: monitoring communications from aplurality of mobile endpoints, each communication comprising a mediamessage and location information identifying a location of itstransmitting endpoint; selecting a first group of mobile endpoints ofthe plurality of endpoints according to virtual talk group configurationinstructions based on the locations of the mobile endpoints; configuringa first virtual talk group comprising the first group of mobileendpoints to facilitate communications among the first group of mobileendpoints, the first group of mobile endpoints comprising mobileendpoints of different communication networks; wherein the first groupof mobile endpoints of the first virtual talk group comprise a pluralityof mobile endpoints of different communication networks whosecommunications are mapped to a multicast IP address; wherein the firstvirtual talk group is associated with a geographical area; furthercomprising determining whether each of the selected first group ofmobile endpoints are within a multicast reach of the geographical area;and wherein configuring the first virtual talk group comprises joiningin the first virtual talk group via multicast each of the selected firstgroup of mobile endpoints that are within the multicast reach of thegeographical area.
 2. The method of claim 1, wherein the virtual talkgroup configuration instructions include instructions to configure avirtual talk group of mobile endpoints within a first distance of afirst event.
 3. The method of claim 1, wherein the virtual talk groupconfiguration instructions include instructions to configure a virtualtalk group of mobile endpoints within a first distance of a mobileendpoint of a user.
 4. The method of claim 1, wherein the virtual talkgroup configuration instructions include instructions to configure avirtual talk group of mobile endpoints within a selected geographicarea.
 5. The method of claim 4, wherein the geographic area is selectedon a map by a user.
 6. The method of claim 1, further comprising:receiving the virtual talk group configuration instructions from a user;and adding a mobile endpoint of the user to the first virtual talk groupsuch that communications from the first group of mobile endpoints arecommunicated to the user.
 7. The method of claim 1, further comprisingremoving a first mobile endpoint of the first group of mobile endpointsfrom the first virtual talk group when the first mobile endpoint leavesa geographic area associated with the first virtual talk group.
 8. Themethod of claim 1: wherein the virtual talk group configurationinstructions relate to a first geographical area and the first virtualtalk group is configured based on mobile endpoints within the firstgeographical area; and further comprising removing a first mobileendpoint of the first group of mobile endpoints from the first virtualtalk group when the first mobile endpoint leaves a second geographicalarea, the second geographical area including and greater than the firstgeographical area.
 9. The method of claim 1, wherein the first group ofmobile endpoints of the first virtual talk group comprise a plurality ofmobile endpoints of different communication networks whosecommunications are bridged.
 10. The method of claim 1, wherein the firstgroup of mobile endpoints of the first virtual talk group comprises landmobile radios operable to communicate on different frequencies.
 11. Themethod of claim 1, wherein communications from the plurality of mobileendpoints comprises push-to-talk communications.
 12. The method of claim1, wherein the different communication networks comprise at least twoof: a police department communication network, a fire departmentcommunication network, an ambulance communication network and a companycommunication network.
 13. The method of claim 1, wherein configuringthe first virtual talk group comprises joining in the first virtual talkgroup via nailed dialed connections each of the selected first group ofmobile endpoints that are not within the multicast reach of thegeographical area.
 14. The method of claim 13, wherein the joining vianailed dialed connections comprises joining using SIP protocol.
 15. Themethod of claim 1: further comprising switching a the-first mobileendpoint of the first group of mobile endpoints to a nailed SIPconnection to the first virtual talk group when the first mobileendpoint leaves the multicast reach of the geographical area.
 16. Themethod of claim 1, further comprising: determining that a first mobileendpoint of the first group of mobile endpoints is continuously movingin and out of the a-multicast reach of the geographical area; and inresponse to the determination that the first mobile endpoint iscontinuously moving in and out of the multicast reach, providing aconnection for the first mobile endpoint to the first virtual talk groupvia a nailed dialed connection.
 17. A system for automatic configurationof virtual talk groups based on location of media source, comprising aprocessor operable to: monitor communications from a plurality of mobileendpoints, each communication comprising a media message and locationinformation identifying a location of its transmitting endpoint; selecta first group of mobile endpoints of the plurality of endpointsaccording to virtual talk group configuration instructions based on thelocations of the mobile endpoints; configure a first virtual talk groupcomprising the first group of mobile endpoints to facilitatecommunications among the first group of mobile endpoints, the firstgroup of mobile endpoints comprising mobile endpoints of differentcommunication networks; wherein the first group of mobile endpoints ofthe first virtual talk group comprise a plurality of mobile endpoints ofdifferent communication networks whose communications are mapped to amulticast IP address; the first virtual talk group is associated with ageographical area the processor is further operable to determine whethereach of the selected first group of mobile endpoints are within amulticast reach of the geographical area; and a processor operable toconfigure the first virtual talk group comprises a processor operable tojoin in the first virtual talk group via multicast each of the selectedfirst group of mobile endpoints that are within the multicast reach ofthe geographical area.
 18. The system of claim 17, wherein the virtualtalk group configuration instructions include instructions to configurea virtual talk group of mobile endpoints within a first distance of afirst event.
 19. The system of claim 17, wherein the virtual talk groupconfiguration instructions include instructions to configure a virtualtalk group of mobile endpoints within a first distance of a mobileendpoint of a user.
 20. The system of claim 19, wherein the virtual talkgroup configuration instructions include instructions to configure avirtual talk group of mobile endpoints within a selected geographicarea.
 21. The system of claim 20, wherein the geographic area isselected on a map by a user.
 22. The system of claim 17: an interfacecoupled to the processor and operable to receive the virtual talk groupconfiguration instructions from a user; and wherein the processor isfurther operable to add a mobile endpoint of the user to the firstvirtual talk group such that communications from the first group ofmobile endpoints are communicated to the user.
 23. The system of claim17, wherein the processor is further operable to remove a first mobileendpoint of the first group of mobile endpoints from the first virtualtalk group when the first mobile endpoint leaves a geographic areaassociated with the first virtual talk group.
 24. The system of claim17, wherein: the virtual talk group configuration instructions relate toa first geographical area and the first virtual talk group is configuredbased on mobile endpoints within the first geographical area; and theprocessor is further operable to remove a first mobile endpoint of thefirst group of mobile endpoints from the first virtual talk group whenthe first mobile endpoint leaves a second geographical area, the secondgeographical area including and greater than the first geographicalarea.
 25. The system of claim 17, wherein the first group of mobileendpoints of the first virtual talk group comprise a plurality of mobileendpoints of different communication networks whose communications arebridged.
 26. The system of claim 17, wherein the first group of mobileendpoints of the first virtual talk group comprises land mobile radiosoperable to communicate on different frequencies.
 27. The system ofclaim 17, wherein communications from the plurality of mobile endpointscomprises push-to-talk communications.
 28. The system of claim 17,wherein the different communication networks comprise at least two of: apolice department communication network, a fire department communicationnetwork, an ambulance communication network and a company communicationnetwork.
 29. The system of claim 17, wherein a processor operable toconfigure the first virtual talk group comprises a processor operable tojoin in the first virtual talk group via nailed dialed connections eachof the selected first group of mobile endpoints that are not within themulticast reach of the geographical area.
 30. The system of claim 29,wherein the joining via nailed dialed connections comprises joiningusing SIP protocol.
 31. The system of claim 17, wherein: the processoris further operable to switch a first mobile endpoint of the first groupof mobile endpoints to a nailed SIP connection to the first virtual talkgroup when the first mobile endpoint leaves the multicast reach of thegeographical area.
 32. The system of claim 17, wherein: the processor isfurther operable to: determine that a first mobile endpoint of the firstgroup of mobile endpoints is continuously moving in and out of themulticast reach of the geographical area; and in response to thedetermination that the first mobile endpoint is continuously moving inand out of the multicast reach, provide a connection for the firstmobile endpoint to the first virtual talk group via a nailed dialedconnection.
 33. A system for automatic configuration of virtual talkgroups based on location of media source, comprising: means formonitoring communications from a plurality of mobile endpoints, eachcommunication comprising a media message and location informationidentifying a location of its transmitting endpoint; means for selectinga first group of mobile endpoints of the plurality of endpointsaccording to virtual talk group configuration instructions based on thelocations of the mobile endpoints; means for configuring a first virtualtalk group comprising the first group of mobile endpoints to facilitatecommunications among the first group of mobile endpoints, the firstgroup of mobile endpoints comprising mobile endpoints of differentcommunication networks; wherein the first group of mobile endpoints ofthe first virtual talk group comprise a plurality of mobile endpoints ofdifferent communication networks whose communications are mapped to amulticast IP address; wherein the first virtual talk group is associatedwith a geographical area; further comprising means for determiningwhether each of the selected first group of mobile endpoints are withina multicast reach of the geographical area: and wherein means forconfiguring the first virtual talk group comprises means for joining inthe first virtual talk group via multicast each of the selected firstgroup of mobile endpoints that are within the multicast reach of thegeographical area.
 34. Logic embodied in a tangible computer readablemedium, the computer readable medium comprising executable code operableto: monitor communications from a plurality of mobile endpoints, eachcommunication comprising a media message and location informationidentifying a location of its transmitting endpoint; select a firstgroup of mobile endpoints of the plurality of endpoints according tovirtual talk group configuration instructions based on the locations ofthe mobile endpoints; configure a first virtual talk group comprisingthe first group of mobile endpoints to facilitate communications amongthe first group of mobile endpoints, the first group of mobile endpointscomprising mobile endpoints of different communication networks; whereinthe first group of mobile endpoints of the first virtual talk groupcomprise a plurality of mobile endpoints of different communicationnetworks whose communications are mapped to a multicast IP address;wherein the first virtual talk group is associated with a geographicalarea; wherein the code is further operable to determine whether each ofthe selected first group of mobile endpoints are within a multicastreach of the geographical area; and wherein code operable to configurethe first virtual talk group comprises code operable to join in thefirst virtual talk group via multicast each of the selected first groupof mobile endpoints that are within the multicast reach of thegeographical area.
 35. A method for automatic configuration of virtualtalk groups based on location of media source, comprising: monitoringcommunications from a plurality of mobile endpoints, each communicationcomprising a media message and location information identifying alocation of its transmitting endpoint; selecting a first group of mobileendpoints of the plurality of endpoints according to virtual talk groupconfiguration instructions based on the locations of the mobileendpoints; configuring a first virtual talk group comprising the firstgroup of mobile endpoints to facilitate communications among the firstgroup of mobile endpoints, the first group of mobile endpointscomprising mobile endpoints of different communication networks; whereinthe first group of mobile endpoints of the first virtual talk groupcomprise a plurality of mobile endpoints of different communicationnetworks whose communications are mapped to a multicast IP address;wherein the virtual talk group configuration instructions relate to afirst geographical area and the first virtual talk group is configuredbased on mobile endpoints within the first geographical area; andfurther comprising removing a first mobile endpoint of the first groupof mobile endpoints from the first virtual talk group when the firstmobile endpoint leaves a second geographical area, the secondgeographical area including and greater than the first geographicalarea.
 36. A system for automatic configuration of virtual talk groupsbased on location of media source, comprising a processor operable to:monitor communications from a plurality of mobile endpoints, eachcommunication comprising a media message and location informationidentifying a location of its transmitting endpoint; select a firstgroup of mobile endpoints of the plurality of endpoints according tovirtual talk group configuration instructions based on the locations ofthe mobile endpoints; configure a first virtual talk group comprisingthe first group of mobile endpoints to facilitate communications amongthe first group of mobile endpoints, the first group of mobile endpointscomprising mobile endpoints of different communication networks; whereinthe first group of mobile endpoints of the first virtual talk groupcomprise a plurality of mobile endpoints of different communicationnetworks whose communications are mapped to a multicast IP address;wherein the virtual talk group configuration instructions relate to afirst geographical area and the first virtual talk group is configuredbased on mobile endpoints within the first geographical area; andwherein the processor is further operable to remove a first mobileendpoint of the first group of mobile endpoints from the first virtualtalk group when the first mobile endpoint leaves a second geographicalarea, the second geographical area including and greater than the firstgeographical area.
 37. A system for automatic configuration of virtualtalk groups based on location of media source, comprising: means formonitoring communications from a plurality of mobile endpoints, eachcommunication comprising a media message and location informationidentifying a location of its transmitting endpoint; means for selectinga first group of mobile endpoints of the plurality of endpointsaccording to virtual talk group configuration instructions based on thelocations of the mobile endpoints; means for configuring a first virtualtalk group comprising the first group of mobile endpoints to facilitatecommunications among the first group of mobile endpoints, the firstgroup of mobile endpoints comprising mobile endpoints of differentcommunication networks; wherein the first group of mobile endpoints ofthe first virtual talk group comprise a plurality of mobile endpoints ofdifferent communication networks whose communications are mapped to amulticast IP address; wherein the virtual talk group configurationinstructions relate to a first geographical area and the first virtualtalk group is configured based on mobile endpoints within the firstgeographical area; and further comprising means for removing a firstmobile endpoint of the first group of mobile endpoints from the firstvirtual talk group when the first mobile endpoint leaves a secondgeographical area, the second geographical area including and greaterthan the first geographical area.
 38. Logic embodied in a tangiblecomputer readable medium, the computer readable medium comprisingexecutable code operable to: monitor communications from a plurality ofmobile endpoints, each communication comprising a media message andlocation information identifying a location of its transmittingendpoint; select a first group of mobile endpoints of the plurality ofendpoints according to virtual talk group configuration instructionsbased on the locations of the mobile endpoints; configure a firstvirtual talk group comprising the first group of mobile endpoints tofacilitate communications among the first group of mobile endpoints, thefirst group of mobile endpoints comprising mobile endpoints of differentcommunication networks; wherein the first group of mobile endpoints ofthe first virtual talk group comprise a plurality of mobile endpoints ofdifferent communication networks whose communications are mapped to amulticast IP address; wherein the virtual talk group configurationinstructions relate to a first geographical area and the first virtualtalk group is configured based on mobile endpoints within the firstgeographical area; and wherein the code is further operable to remove afirst mobile endpoint of the first group of mobile endpoints from thefirst virtual talk group when the first mobile endpoint leaves a secondgeographical area, the second geographical area including and greaterthan the first geographical area.